A pro diver should be, but a paying customer is the key, should he be doing solo accents in any conditions not only bad, but dangerous.String:I still think that as professional divers you should be able to look after yourself and not have to rely on some guide to keep you out of trouble. If you AREN'T capable of doing that you really ought not to be diving at all.
The customer is not the one who has to look after the group, the PRO is (the D/M).
Here in the USA, as in most places, if a dive center sends you out with a D/M and the D/M gets in the water to lead the dive, he has a duty to see his customers get back to the boat safely. Once out of the water, the customer is the boat crew's problem. I see the question was, should a dive master send up a lone diver the single thing agreed on is plan the dive, dive the plan.
The dive the plan rule is in use in the UK, I know. I taught there, and in both BSAC and Padi, the buddy system is the first thing you learn. If the system fails we all know what can happen.
The largest group of divers in the USA is the vacation diver, who has no equipment (how many who read this can say that they have no equipment) he has not dove for xxx years or at best 1 or 2 years and sometimes only doing a dive to get a little non family time. So who here is volunteering to dive with the guy? He will have little to no idea what weight to use, and he will be putting his gear together wrong. Who has seen and snickered as the guy lifts his cylinder up to put his BC on it? Who has watched the poor guy pull his tank strap apart and have no idea how to put it back together?
Putting the first stage on the cylinder facing the wrong way or worse the wrong side so the valve is not even on an o-ring??
So the guy needs a buddy, still want to buddy with him? The list goes on and on, and the DM is a baby sitter. Our mystery diver needs a class, but he is not going to get one. People like our mystery diver are not uncommon, and should not be on a boat without a refresher course. We know but the truth is these things don't always get caught in the pre dive screening, as they could be the guy or gal who lies about their experience, and fills in log book pages that were not real dives (gasp). But the sad truth is, if the store screened each diver, the boat would not leave the dock as they called the guys' buddies and talked about the dives they had done. You see the problem.
Now ask yourself this. If this guy is so out of practice, good chance he is over weighted, unfamiliar with equipment, and unlikely to have used the BCD other than to have let air out on the way down... would you still feel safe letting our mystery diver go up on his own? My guess is NO, and rightly so.